Which of the following is true regarding active transport? Choose 1
А
It allows particles to pass easily between lipids in cell
membranes.
B
An input of energy is not needed for it to occur.
C
It moves particles from areas of high concentration to
areas of low concentration.
D
It occurs against the concentration gradient.​

answer: c.

explanation:

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.

diaria maybe go see a doctor about that